Adam – one of multiple disciples of Dr.Sevrin, who were brought aboard the USS Enterprise in 2269 – sang a song that contained the word "gavel" upon Captain James T. Kirk refusing to release Sevrin from medical confinement (since he was a carrier of synthococcus novae). The lyrics Adam sang were, "Stiff man putting my mind in jail. And the judge bang the gavel and say, 'No bail.' Gonna lick his hand and wag my tail." (TOS: "The Way to Eden")

In the script for Star Trek VI, the judges' gavel in that film was described as "a grotesque mailed glove," mistaking the gavel for the glove that holds it. [1]

A concept drawing for the Star Trek VI gavel was created by Nilo Rodis-Jamero. (The Art of Star Trek, p. 267) Props master Gregory Jein carved the ball shape out of green foam, then had one of his employees in the props department cast the actual ball. Jein was aware of deviating from the red paint scheme commonly associated with the Klingons, opting to give the gavel a weathered steel finish. The prop was made so that streaks of light would burst out of the cracks in the gavel as it was struck. However, there was a difficulty with the gavel's interior light during filming. "The actor got too enthusiastic and the light broke on the second or third take," said Jein. (The Making of the Trek Films, 3rd ed., p. 128)

"Judgment" writer David A. Goodman was not entirely certain whether the sparks from the gavel in that installment were added in post-production or involved live pyrotechnics. However, he reckoned that at least some of the sparks were probably added after-the-fact, remarking, "I don't know that there's any way they could have done that live." ("Judgment" podcast/audio commentary)

The sketch by Rick Sternbach

The Bajoran gavel seen in "Dax" was sketched by Rick Sternbach and made out of real stone by the art department. (DS9 Season 1 DVD special feature "Deep Space Nine Sketchbook")

A gavel was scripted to appear in TNG: "Devil's Due", to be used by Data while acting as arbiter of a trial to determine whether an apparently non-corporeal lifeform was Ardra, but no gavel appears in that episode's final version. [2] Similarly, the script for DS9: "Tribunal" mentioned a gavel though none is technically shown in that installment either, with the episode's teleplay specifying that Makbar uses "not a gavel but a symbolic rock." [3]